This alert expired on 2 September 2026 at 21:30 UTC. It is kept here as a record.
It is the 5th strongest of the 12 detections recorded within 20 km of this point since 4 April 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Special Marine Warning issued September 2 at 4:05PM EDT until September 2 at 5:30PM EDT by NWS Detroit/Pontiac MI
Nearby, since 4 April 2026
- July 1, 2026 · score 22 · 4.2 km
- September 2, 2026 · score 16 · 8.8 km
- June 10, 2026 · score 16 · 9.9 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 16 out of 100, at 61 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 16 / 100 |
| Our confidence | 61% |
| Coordinates | 43.5614, -82.4071 |
| Nearest City | Sarnia (65 km) |
| Impact Tier | minor |
| Timestamp | 2026-09-02T20:05:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.55648f371e016614786e13449b74a57338a7742c.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Port Austin to Harbor Beach MI; Harbor Beach to Port Sanilac MI; Port Sanilac to Port Huron MI; Lake Huron from Port Austin to Harbor Beach 5NM Off Shore to the US/Canadian border; Lake Huron from Harbor Beach to Port Sanilac 5NM Off Shore to US/Canadian border; Lake Huron from Port Sanilac to Port Huron 5NM Off Shore to US/Canadian border |
| Headline | Special Marine Warning issued September 2 at 4:05PM EDT until September 2 at 5:30PM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-09-02T17:30:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
Series begins 8 March 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
Want to know when something happens in this area?
Calamity.live data shows a weather event with CalamityScore 16/100 (Canada), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.